So i had my Check Engine Light turn on took it to AutoZone and p0440 code came up so i changed the gas cap, but he wouldnt reset my light so iv driven the car with the light on for almost 3months now and light turned off yesturday and has been off since. So did it reset it self or is the code still in the Computer where i would fail the epa test.

Thanks

 

The P0440 code has been discussed quite a bit in the past. If the gas cap did not fix the problem, then there likely is something wrong with the vent solenoid. If the light is now off, then the problem has not been detected by the PCM, but that does not mean that it may not come back.

 

The dreaded PO440. Mine threw this code for six months straight. Changing the gas cap did nothing. I got to where I just ignored the SES light. It finally stopped(the SES light), on it's own, and hasn't appeared again. And it's been like 5 months now. Go figure.

I think these things should have an "ignore" function, where you can tell it to ignore specific codes.

 

I can only imagine what the result of that would be like.

 

Ok so i took it in a shop for this P0440 code. first i had to buy the oem gas cap cuz the one i bought at autozone wasnt maintaining a seal. he then check everthing else and everthing was working ok the only thing that he didnt get was that when the system runs the test when the truck is not moving the gas tank presure suppose to maintain between 15% and 85% wich it does but when the truck is moving it doesnt maintain it between there so the test cant be complete. So what could this result to? is there something with in the tank that i need to look into or replace? Thanks

 

The shop tested both opening and closing them, i have new oem gas cap and still P0440 code. Everyone seems to say change the vent one is it possiable that even if they tested it might be still bad. And as i checked the front solenoid how thight is the hose suppose the be i could rotate it clock wise and counter clock wise alittle with the clip on is this normal? Thanks

I found a lose cracked hose on top of the fuel tank near the corner of the tank by the drivers side door. I havent droped the tank down yet to find out where it belongs but would the hose be connected to the vent on the tank and if so would this cause my P0440 . Thanks

 

You didn't say what you're driving but I assume a four door. Yes that will cause that code. Lower the tank and on top of it is a plastic nipple it fits on and it's easier to access if you loosen the clamps and drop the tank two inches.

 

Depends on how they tested them. So you took it to a shop and they did not cure the problem? Hopefully they did not charge you.

A smoke test can be performed and positively identify the leak point.

Please keep all of the P0440 related questions in one place. I have combined them all together to provide the background and discussion points of them all in one convenient location.

 

Sorry for the post up on this problem. Yes i have a 4door if the vent valve is broke do i have to completely drop the tank to replace it or would a few inches do? Thats what he is planning to do next is the smoke test 35$ then i would have to pay but i get a 30day warranty if the light keeps coming on.

 

You should not have to drop the tank all the way to the ground. You will have to be careful about how far you drop it though.